Replace Your Old Windows and Save! Not Likely.

‘Tis the season for window salespeople, contractors, and other parties who either have skin in the game or are incorrectly informed to try to sell you on the idea of replacing your old windows to save energy. STOP. Very simply put, if your windows are original to your house, you should think long and hard before replacing them with double-pane, insulating units. Not only are original windows key to a house’s look, an old wood window can be made to operate well; with a good storm window over it, it can equal the energy performance of a modern window. Do not believe anyone who tells you that new windows “will pay for themselves.”

Let me put forward a scenario:

Assume $300 per new window in installation cost (and that’s cheap). How long will it take to make that up in energy savings? Windows account for, at most, somewhere between 20% and 30% of your house’s energy loss. So, take 25% of your yearly heating bill (heat loss through windows), then take 10% of that number (improved efficiency with a low-e double-glaze replacement window over an old window with a storm window). The result is the amount of money you could expect to save in energy use. Replace 25 windows at a cost of $300/window: total installation cost = $7,500. Let's assume $5,000 in annual heating and cooling costs. 25% of $5000 goes out the windows = $1250. Now, 10% of that you will save in energy use = $125. SO...in 60 YEARS (not accounting for inflation) you will have earned your money back. Of course, during that time you also will have replaced your replacement windows at least once, because very rarely will modern windows last that long.

For more information, visit the website of David Liberty, one of the Boston area’s best old-window specialists.

In defense of modern window manufacturers—employees of which I count among my best friends in the building industry--quality new wood windows most definitely have a place in new houses, in additions, and to replace replacement windows that were crummy to start with.